The present invention relates to linear electrodynamic machines, and more particularly, to an electromagnetic actuator.
Linear electric motors have increasingly been applied to a number of applications where precise displacement is required. Generally, a linear motor includes a selectively energized winding positioned in close proximity to a plurality of magnets. In many linear motors, the magnets are held stationary and the winding is energized so that magnetic fields created by the winding interact with the magnetic fields of the permanent magnets to cause displacement of the winding relative to the permanent magnets. In other motors, the magnets are disposed on a movable rod while the stator winding is held stationary.
Recently, there has been interest in replacing conventional hydraulic actuators with linear motors or, more appropriately called, electromagnetic actuators in this application. It is commonly known that although hydraulic actuators can develop high forces, hydraulic actuators typically are just a part of a larger hydraulic system that requires other complicated devices such as accumulators, filters and pumps which all must be maintained in order to operate. Furthermore, being that the hydraulic system operates using pressurized fluid, there is always the risk of a fluid leak.
Although known electromagnetic actuators can provide precise control of the moving armature, these actuators have as of yet not replaced hydraulic actuators because sufficient forces comparable to the hydraulic actuators have not yet been obtainable.